Add country-based access control managed through the Settings page.
Global allow-list with per-app overrides, searchable country selector,
automatic sync to Cloudflare WAF on settings change / deploy / remove,
plus periodic 6-hour verification.
New package: internal/cloudflare/ (client, zone, waf, countries, geosync)
New API: /api/geo/* (6 endpoints) + /api/stacks/{name}/geo/override
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
